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To observe the fish gills with the optical microscope, the scientists used two different stains - AQA - A-Level Biology - Question 8 - 2022 - Paper 1
Question 8
To observe the fish gills with the optical microscope, the scientists used two different stains. The first stain binds to DNA; the second stain binds to the red bloo... show full transcript
Worked Solution & Example Answer:To observe the fish gills with the optical microscope, the scientists used two different stains - AQA - A-Level Biology - Question 8 - 2022 - Paper 1
Step 1
Explain why a second stain would be needed to stain the red blood cells.
Answer
Red blood cells do not have a nucleus or DNA, so the first stain would not be effective. A second stain is required to bind specifically to the hemoglobin present in red blood cells. Hemoglobin is the molecule that carries oxygen and gives red blood cells their color.